Substance
Substance (Coelest IV) was a deep blue gas giant that orbited the star Coelest. It was a relatively calm giant that hosted a singular Halo ring, Installation 05. Substance itself only had one natural moon, Opusculus, which served as a gravity anchor for the Installation. Though Opusculus was the only natural moon, Substance had an additional seven satellites that orbited it. These satellites were very likely of Forerunner origin. Substance itself was composed mainly of Hydrogen and Helium, but the planet itself had a very high amount of methane, which is what gave Substance its dark blue coloring. No noticable band structure was visible in the cloud layers, but storms were quite common within the atmosphere. One particular storm formation near the equator was notable. The name for this formation was the 'Subtle Storm', but the windspeeds were capable of reaching well over three thousand kilometers per hour. Because of its position, Substance itself was located beyond the frost line of the Coelest system, which classifies the planet as an ice giant. It orbited Coelest at fifty Astronomical Units. Planetary Description As with many gas giants, Substance did not have a solid surface to stand upon. The planet itself was believed to have a rocky core at the center of the planet. The core itself was surrounded with a sea of hydrogen which was rendered liquid due to the extreme pressures. It was impossible for life to exist at these depths, though probes have been able to see forks of lightning stretch hundreds of kilometers through the dense gas. Despite being in a position where the planet is classified as a gas giant, Substance seems to have heat that is generated within the planet similar to Neptune. The reason for this is not quite known, but it is believed that tidal forces between the planet and Opusculus is the reason for this. Threshold has a diameter of 82,749 kilometers. For comparison, Earth's diameter is only 12,742 kilometers. This makes the planet Jupiter 1.72 times larger than Substance. The planet also has liquid vapor in the atmosphere that condenses and rains. This liquid is mainly water and Ammonia vapor which is scattered throughout the cloud layers. At some points, the water vapor forms cirrus clouds that appear very Earth-like. Clouds of water-methane are also common on the planet, but these seem to be mid level cloud structures. Closer to the cloudtops, the temperature of Substance is a chilly -240 degrees Celsius, though with the massive internal heat sources, it's likely that the closer one got to the core, the temperature was sure to reach, if not exceed, 10,000 degrees Celsius. As with the planet Threshold, scientists noted that the planet seemed to lack the numbers of natural satellites that are common in gas giants, with Opusculus being the only natural moon that the planet possesses. Two theories arose from this data: the first is that the Forerunners were able to combine all of the mass in the planetary system to form Opusculus, which serves as the gravity anchor for Installation 05, which lies at the Lagrange Point between the planet and the moon. The second theory is that the moons were mined to provide materials for the Installation or the other Forerunner installations in orbit around Substance, but records suggest that the moons were not used for the purposes of the Installation at all. In any case, Forerunner interference in the shaping of the planetary system is hinted at strongly. Substance rotates in different amounts due to the band structure of the planet, meaning that a technical 'rotation' can last a different time depending on the location on the planet. It is agreed upon though that Substance seems to have a 13 hour day. However, due to it's extreme distance from the sun, Substance has a 310 year revolution period. Installation 05 As the planet served as the main source of gravitational stability for the ringworld, it is possible to view the planet from any part of the ring except for the instance when the rotation of the ring meant that the planet was 'below' the observer. Installation 05 has a thicker atmosphere than some of the other Halo rings, which means that sometimes weather may prevent direct sighting of the planet. Though when the planet is indeed visible, it is said to evoke a tranquil feeling from observers. At night, especially 'Halo Night', Substance reflects a certain amount of light from Coelest. This can actually create a feeling of twilight to those that are on the surface of the ring. Tourists and citizens are said to be able to read via 'Stance Light. When Opusculus is properly positioned in sunlight, it too can reflect light. Some have said that the feeling that it brings is similar to twilight on other planets. Substance also serves as a gas station for passing ships and for the citizens of the rings. mining stations in orbit around the planet often ship the refined gas to Installation 05 which is used as fuel by the citizens, or it is shipped out on cargo ships. List of Appearances *Deception (First Appearance) Category:Planet Category:Locations Category:Gas Giant